The present invention relates to an analog switching circuit device for use in a semiconductor integrated circuit.
An analog switching circuit is one that transmits an analog signal in one direction or in two directions by switching. In general, various kinds of electronic equipment such as computers and controlling devices comprise a plurality of circuit boards therein, each circuit board being connected to a common bus line. For example, an analog switching circuit is provided in each circuit board and the circuit board is connected to the common bus line through the analog switching circuit, whereby signals are transferred between the circuit boards.
For the analog switching circuit, in the bus line application using a plurality of analog switching circuits connected each other through the bus line, in the case where a power source potential of at least one of the analog switching circuit is set to a ground potential and this analog switching circuit is in a non-operative state, when other analog switching circuits outputs a potential higher than the ground potential, a drawback that a current flows through the parasitic diode of the analog switching circuit, which is in the non-operation state, is produced.
Furthermore, where the analog switching circuit is designed so that such a current does not flow therethrough, the output level onto the bus line reduces and the circuit does not perform full-swing.